Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)
The term CIDP refers to a chronic form of an acquired inflammatory polyneuropathy that is clinically differentiated from AIDP by its time course. CIDP encompasses a spectrum of phenotypic variants with common features of chronicity, demyelination evident on the nerve conduction studies, and albuminocytological dissociation in the CSF.
Classical CIDP is characterized by symmetrical proximal and distal muscle weakness, sensory loss, and hyporeflexia or areflexia, with either a relapsing or progressive course . Proximal weakness and upper extremity involvement are common in classical CIDP, which is in contrast to most other types of polyneuropathy which are generally characterized by a more distal pattern of involvement . Sensory changes may include numbness, paresthesias, and difficulty with proprioception and balance. Neuropathic pain is a rather infrequent feature in CIDP , but rarely pain is the presenting feature . Respiratory compromise and dysautonomia are uncommon in CIDP (in contrast to GBS) and occur in less than 10% of patients . Facial, ocular, and oropharyngeal involvement is infrequent as well and is estimated to occur in about 15% of patients . CIDP is differentiated from GBS by its time course: the time to nadir in CIDP is more than 8 weeks (it is usually <2 weeks and maximally 4 weeks in GBS) . In two thirds of those affected, the disease has a progressive course, with the remainder experiencing relapses.